I don't know how helpful this answer will be. I make up Kickers by considering everything about the character.

However, that is not the same thing as saying that everything about the character must contribute to the Kicker. It means that I look over everything and see either stuff that can be extended ("the guy has a family, let's add a member who was previously unknown") or stuff that offers a window for a sharp contrast ("the guy is a grim ex-military survivor with no love in his history or present ... what if he just fell in love?"). By stuff I mean any or all elements currently made up, but usually only a couple.

All of that should also be taken in the context that the steps of character creation may be carried out in any order. So inspiration for the Kicker can arise with almost no such information available, with the full range, or anything in between.